Separation process and apparatus for removal of particulate material from flash zone gas oil

ABSTRACT

A process and an apparatus for removing particulate material from a flash zone gas oil stream produced in a delayed coking unit. The process and apparatus of the invention employ cyclonic separation to remove particulate material from the flash zone gas oil stream. The stream can then be further processed, for example by passing the stream to a fixed bed catalytic hydroprocessing unit and then to a fluidized bed catalytic cracking unit, or to other processing units, thereby enhancing the value of the flash zone gas oil stream.

TECHNICAL FIELD

The present invention relates to delayed coking processes, and moreparticularly to a process and an apparatus for removal of particulatematerial from a flash zone gas oil stream in a delayed coking unit.

BACKGROUND

In a delayed coking process, overhead vapors from a coke drum are passedto a coke fractionator wherein the coker overheads are separated into avapor stream, one or more intermediate liquid streams, and a flash zonegas oil (FZGO) stream. The FZGO stream often contains significantamounts of finely divided particulate solids (e.g. coke fines) ofvarying diameter, as well as heavy viscous mesophase material. Themesophase material can be liquid coke that is entrained in the vaporsleaving a coke drum and is often coated on coke particles, making theparticles sticky. In order to enhance the value of an FZGO stream,further processing is necessary, and it is desirable to pass the FZGOstream to, for example, a fixed bed catalytic hydroprocessing unit andthen to a fluidized bed catalytic cracking (FCC) unit or to otherprocessing units. Undesirably, however, entrained solids and mesophasematerial in the FZGO stream can quickly plug and foul the catalyst bedof the hydroprocessor.

Unhydrotreated flash zone gas oil can be processed in a fluidized bedcatalytic cracking unit (FCC unit), but the yield distribution of theunhydrotreated FZGO stream is generally poor due to its highly aromaticcontent and other factors.

A filter medium can be used to filter out particles from the FZGOstream. However, filtration processes are susceptible to filterplugging, can require significant periods of shutdown to clean or removetar or gum build up to regenerate the filter medium, and can requiresignificant initial capital expenditure to install.

It would be advantageous, therefore, to provide a process and anapparatus that operate efficiently and economically to removeparticulate material from the FZGO stream, thereby facilitatingsubsequent processing of the FZGO stream and providing an opportunityfor improving refinery economics by enhancing the value of the FZGOstream.

SUMMARY

The present invention provides a process and an apparatus for removingparticulate material from a flash zone gas oil stream, includingparticulates that are about 15 micrometers to 25 micrometers or more indiameter. According to the invention, cyclonic separation technology isused to centrifugally remove particulate material from the FZGO streamto form a reduced particulate stream. The reduced particulate stream canthen be further processed, for example, in a hydroprocessing unit andsubsequent fluidized bed catalytic cracking (FCC) unit, to providevaluable products. Removing the particulate material from the FZGOstream before it enters a hydroprocessing unit allows the stream to beprocessed without, or with reduced incidence of, plugging of thehydroprocessing unit catalyst bed.

In an aspect of the invention, an improved delayed coking process isprovided, wherein overhead vapors from a coking drum are fed to a cokerfractionator where the vapors are separated into an overhead vaporstream, intermediate liquid streams, and a flash zone gas oil streamcontaining a substantial amount of particulate material of varyingdiameter, the improved process further comprising the steps of supplyingthe flash zone gas oil stream to a first separator;

operating the first separator to remove particulate material having adiameter greater than about 500 micrometers from the flash zone gas oilstream and form a first reduced particulate stream;

supplying that reduced particulate stream to a second separatorcomprising a cyclonic separator;

operating the second separator to remove particulate material having adiameter greater than about 25 micrometers from the reduced particulatestream and form a second reduced particulate stream; and

supplying the second reduced particulate stream to a hydroprocessor.

In another aspect the invention is an apparatus comprising a coking drumthat generates overhead vapors, a coker fractionator that receives theoverhead vapors from the coking drum and separates them into an overheadvapor stream, intermediate liquid streams, and a flash zone gas oilstream containing a substantial amount of particulate material ofvarying diameter, and a hydroprocessor located downstream from saidfractionator, the improved apparatus further comprising

a first separator located downstream of said fractionator and configuredto receive the FZGO stream from the fractionator and remove theparticulate material having a diameter greater than about 500micrometers from the FZGO stream to form a first reduced particulatestream; and

a second separator comprising a cyclonic separator located downstream ofsaid first separator and configured to remove particulate materialhaving a diameter greater than about 25 micrometers from the firstreduced particulate stream to form a second reduced particulate stream.

In a further aspect of the invention, an apparatus that includes twoseparators is provided, where at least one of the separators is acyclonic separator having a manifold of cyclones.

The process and apparatus of the invention can advantageously operatecontinuously on-line without periodic shut downs for back flushingclogged equipment, resulting in lower maintenance and operating costs.Compared to conventional methods, the process and apparatus of theinvention can advantageously be implemented with a low initial capitalcost. The process and apparatus of the invention also present anopportunity for improving refinery economics by facilitating furtherprocessing of the FZGO stream and permitting the use of hydrotreatedFZGO as FCC unit feedstock rather than as delayed coker natural recycle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flowsheet depicting a delayed-coking process.

FIG. 2 is a schematic flowsheet depicting an embodiment of the processof the invention.

FIG. 3 is a schematic flowsheet depicting another embodiment of theprocess of the invention.

FIG. 4 is a schematic flowsheet depicting a further embodiment of theprocess of the invention.

FIG. 5 is a partial cutaway perspective view of a preferred cyclonicseparator.

FIG. 6 is a partial cutaway side view of a preferred cyclonic separatorsuitable for the invention.

FIG. 7 is an exploded, partial cutaway perspective view of the cyclonicseparator of FIG. 6.

FIG. 8 is a partial cutaway perspective view of an individual cycloneuseful in the separator of FIGS. 6 and 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a basic delayed coking process 5. Coking process 5can convert feedstock into a gas overhead stream, one or moreintermediate liquid streams and a FZGO stream. In operation, a feedstock10 passes through a furnace 15 and then enters one of two coke drums 20Aor 20B. Overhead vapors 25 that exit from the coke drums are quenchedand then fed into fractionator 30. A liquid 35, such as a heavy gas oilor a recycle liquid, is sprayed into the flash zone of fractionator 30,where the flash zone is typically located in the lower to middle regionof the fractionator. The heavy gas oil 35 can serve two purposes: toknock down suspended particles in the vapors as they enter thefractionator, and/or condense components with higher boiling points fromthe vapors. A wet gas overhead stream 40 exits from the top offractionator 30, while one or more intermediate liquid streams 45, 50,55 exit from the side of fractionator 30. The resulting FZGO stream 60that may contain suspended coke particles and viscous mesophase materialthat may coat such particles and make the particles sticky (hereinaftercollectively called “particulate material”) exits near the bottom offractionator 30.

In conventional methods, a FZGO stream 60 is generally not fed to ahydrotreater due to rapid catalyst fouling from the suspendedparticulate material. As a result, the FZGO stream, may be fedunfiltered to an FCC unit. Undesirably, however, the oil stream's highlevel of aromatic compounds results in poor product yield distribution.Additionally, the FZGO stream often contains undesirable levels ofsulfur and could cause the stream exiting the FCC unit to exceed theindustry mandated sulfur levels in the gasoline, kerosene and dieselproduct streams of the refinery. In some instances, an FZGO stream wouldbe used as a lower value stream such as those used to produce highsulfur fuel oil.

Removing particulate material from an FZGO stream advantageouslyenhances the value of an oil stream by allowing it to be processedfurther to obtain useful and valuable products. In particular, a reducedparticulate oil stream could be fed to a fixed bed catalytichydrotreater without fear of fouling the catalyst bed. Thus, directingan FZGO stream 60 such as that obtained from a process depicted in FIG.1 to a separation process would be desirable, as it can be furtherprocessed in units such as an FCC unit to produce valuable products.

The present invention provides an improved process and apparatus forseparating particulate material suspended in a flash zone oil streamfrom the oil stream itself, using at least one cyclonic separation unitor separator. In a preferred aspect, the second separator is a cyclonicunit comprising a plurality of cyclones provided in a manifold. Thisseparator is implemented to remove particulate material that have adiameter of greater than about 15 micrometers from an oil stream that isultimately intended to enter a catalytic cracking unit. A separatorlocated upstream from the cyclonic separator can be implemented toremove larger particulate material that are greater than about 75micrometer in diameter, to prevent plugging of the cyclonic separator.

Referring now to FIG. 2, one embodiment of the present invention isillustrated, that includes a separator 65 implemented in series with acyclonic separator 80. Separator 65 preferably removes the largerparticles from the FZGO stream, such as those having a diameter greaterthan about 500 micrometers. Cyclonic separator 80 substantiallyseparates and removes the smaller particles, such as those having adiameter greater than about 25 micrometers. If a “cleaner” oil stream isdesired, separator 65 can be configured to separate particulate materialhaving a diameter greater than about 100 micrometers; and preferably,particulate having a diameter greater than about 75 micrometers.Similarly, for “cleaner” oil streams, cyclonic separator 80 removesparticulate material having a diameter greater than about 15micrometers.

In preferred operations, separation unit 65 separates at least about 80%of the particulate that has a diameter greater than about 500micrometers. More preferably, unit 65 separates at least about 90% ofthe particulate greater than about 500 micrometers. Similar levels ofseparation efficiency would be desirable for particulate material havinga diameter greater than about 100 micrometers, as well as forparticulate material having a diameter greater than about 75micrometers.

Separator 65 can be any device capable of separating, displacing,removing, stripping, filtering, or combinations thereof, the particulatematerial (e.g. solids and other non-fluids) from a fluid stream.Suitable devices for separator 65, include for example, a strainer, asieve, a filter, a cyclonic separator, or combinations thereof. In anaspect of the invention, separator 65 is a basket strainer. The strainercan include a wire mesh of about 75 to about 100 micrometers. Othersuitable designs include, for example, a duplex or a simplex strainer.In another aspect of the invention, separator 65 comprises a cyclonicseparator. This will be described in greater detail in the discussionabout FIG. 3 below.

Continuing with the process as depicted in FIG. 2, a reduced particulateoil stream 70 exits separator 65 and is subsequently fed downstream tocyclonic separator 80. In a preferred aspect, cyclonic separator 80includes a plurality of individual, preferably small-sized, cyclonescontained within a manifold, inside a housing or vessel. A preferredseparator 80 is illustrated in FIG. 5, the contents of which will bediscussed in detail below. In preferred operations, cyclonic separator80 separates at least about 80% of the particulate having a diametergreater than about 25 micrometers. More preferably, unit 80 isconfigured to separate at least about 90% of the particulate greaterthan about 25 micrometers. Similar levels of separation efficiency wouldbe desirable for particulate material having a diameter greater thanabout 15 micrometers.

Overflow stream 90 from cyclonic separator 80, having a reducedparticulate level, can be fed to a hydroprocessing unit 95 where it isprocessed to be suitable for further processing in a catalytic-crackingunit 100, such as a fluidized bed catalytic cracker (FCC). An underflowstream 85 exits the lower region of cyclonic separator 80, carrying awaythe particulate material displaced from the oil stream 70.Hydroprocessor 95 may be a hydrotreater, a hydrocracking unit, or ahydrodesulfurizer, and typically includes a fixed bed catalyst.

As also shown in FIG. 2, an optional stream of heavy gas oil 55 may besupplied as a feed stream 55A directly to separator 65 to act as adiluent which makes the stream less viscous. This helps prevent pluggingof the line, as the stream is carried back to the cyclone 80.

Optionally, a heavy coker gas oil (“HCGO”) can be admixed to anunderflow stream leaving a separator to avoid plugging the underflowlines. The HCGO can be both a flush oil as well as a distillate recycleto dilute the concentration of coke particles in the stream. Use of anHCGO stream also increases the total liquid volume within the processand helps maintain necessary flow velocities in the process' conduits.

FIG. 3 provides another embodiment of the present invention whereinseparation of particulates from an FZGO stream is accomplished using aseries of cyclonic separators. Here, separator 65 is a cyclonicseparation unit preferably configured and designed sufficiently large tooperate at commercial-coking flow rates, temperatures, and separationefficiencies. As a two-stage cyclonic separation process, unit 65 isoperated to substantially remove large particulate material having adiameter greater than about 500 micrometers, while downstream cyclonicseparator 80 removes the smaller particles. Preferably separator 65removes particulate having a diameter greater than about 100 micrometersand more preferably particulate having a diameter greater than about 75micrometers. Advantageously, by removing most of the larger sizedparticulates from the FZGO stream, cyclonic separator 80 can be operatedefficiently, with the potential or frequency of plugging minimized ifnot eliminated. Preferably, separator 65 operates at separationefficiencies (percent removal) similar to that described above in FIG.2. To sustain general commercial coking process parameters, the nominaldiameter of a cyclonic separator 65 is preferably between about four andten inches. This may change, however, depending on the length of thevessel, desired throughput, and/or other process parameters that couldaffect the separation process.

As shown in FIG. 3, FZGO stream 60 enters separator 65, where it isprocessed to remove the larger particulates from the FZGO. An overflowstream 70 having a reduced level of particulate material exits separator65, while an underflow stream 10 exits the lower region of separator 65.Underflow stream 10 contains the centrifugally displaced particulatesfrom FZGO stream 60.

In the practice of the invention, there may be desired velocities,volumes, and volumetric flow rates that maximize a process' efficiencyand productivity. In an aspect of the invention, where industrialvolumes are processed in commercial-worthy timelines, a separator suchas 65 or 80 is operated with a pressure drop sufficient to sustain thevolumes and flow rate through the process. Furthermore, it has beenfound that sufficient pressure drop can ensure efficient, unencumberedoperation of a separator. Thus, for example, where separator 65 is acyclonic vessel as shown in FIG. 3, the unit is preferably operated witha pressure drop of at least 10 psig. More preferably, the unit isoperated with a pressure drop of at least 20 psig. In preferred aspects,cyclonic separator 80 is operated with a pressure drop of at least 25psig; more preferably, the pressure drop is at least 50 psig.

Optionally, heavy gas oil streams 55A and 55B produced by fractionator30 can be directed to unit 65 and 80, respectively, as shown in FIG. 3.Directing stream 55A to separator 65 may be advantageous where asignificant amount of large particles are in the heavy gas oil stream.If there are very few large particles, then stream 55B is preferablydirected to separator unit 80 to reduce the pump pressure requirements.Also, an optional stream of distillate flush oil can be mixed withunderflow stream 110 to prevent plugging of the underflow lines.

A further embodiment of the invention includes at least three separationunits as shown in FIG. 4. The third separator 105 is preferably locateddownstream for separator 65 and upstream from separator 80. Separator105 can be yet another cyclonic separator, a strainer, a filter, or anyother solid removal device. The separation device in unit 105 ispreferably deigned to be capable of removing particulate material froman oil stream, and therefore serves to be either a back-up for periodswhen unit 65 is inoperative or down, or as a second assurance that largeparticulate are removed from the oil stream prior to entering cyclonicseparator 80.

Optionally, the underflow stream 85 originating from cyclonic separator80 can be combined with the underflow stream 110 from separator 65 toform a combined underflow stream (not shown) that can be returned tocoker fractionator 30 as natural recycle. A moderate amount of thecombined stream is preferably used. Thus, the volume of the two combinedunderflow streams, not including any distillate flush oil with whichthey are mixed, is preferably less than about 5% of the total FZGOstream, but can be as low as about 1.5% of the total FZGO stream.

The flow rate of the various streams within the process can becontrolled with a variety of instrumentation and equipment as is knownin the art. Thus, additional equipment and apparatuses such as valves,controllers, flowmeters, indicators, etc., can be added to the process,although not depicted in the flowsheets of FIGS. 1-4. Furthermore, theuse of a heavy coker gas oil can also be added as a flush oil toalleviate potential plugging in the process.

Cyclonic separators useful for the methods of the invention are thosemodeled after cyclones, where elongate vessels are designed with inletports strategically placed tangential to the vessel body, such that avortex is produced as fluid flows into the vessel. Using centrifugalforce, denser material (e.g. solids or particulate material) are removedand separated from the FZGO stream. Cyclonic separators suitable for theinvention can range in size (e.g., nominal diameter) from about 0.5 inchto about 15 inches. The size (e.g. diameter of a single cyclone toremove large particulate, or the number of cyclones in a multi-cycloneunit) can vary, as the size is determined by an intended quantity(volume) of fluid throughput.

For acceptable operation of a cyclonic separator in a delayed cokingprocess of the invention, several factors could determine how a cyclonicseparation unit is designed and configured (e.g. size, diameter,length). These factors include, for example, the desired liquidthroughput, the size of particles intended to be removed, and processefficiency. Determining the cyclone size is generally the first step;the flow rate through the apparatus can then be determined based on thatsize. For multiple cyclone units (i.e. a manifold of cyclones), thenumber of cyclones needed to achieve the desired process efficiency canbe determined by dividing the total desired flow rate for the system bythe flow rate per cyclone.

The ability of a cyclone to separate particulate material from a liquidis based on various factors. These include, the difference between thespecific gravity of the liquid and the specific gravity of theparticulate, as well as the centrifugal force within the hydrocyclone.The centrifugal force within the cyclone is determined by both theviscosity of the liquid and the pressure drop across the cyclone. In thepresent invention, the liquid is typically a FZGO stream, which is aheavy oil fraction. This type of stream can be a gel at ambienttemperatures. However, as an FZGO stream leaves a fractionator, itstemperature is generally between about 600° F. to about 800° F. (315.6°C. to 426.7° C.) depending on the coke drum cycle. The specific gravityand viscosity of an FZGO stream varies, depending on its temperature.Thus, it is preferred that a cyclonic separator for the process andapparatus of the invention is operated at temperatures of about 600° F.to about 800° F. (315.6° C. to 426.7° C.) to ensure acceptable operationand efficiency.

Referring now to FIG. 5, a cyclonic separator 80 suitable for theinvention is illustrated, wherein the unit includes multiple cycloneunits 134, each configured to centrifugally remove small particulatematerial. Individual cyclones 134 are preferably arranged adjacent andparallel to one another inside a vessel body 136 and held in place toprovide a manifold of cyclones. By using a plurality of the individualunits, the cyclonic separator 80, as a whole, can operate to processcommercial or industrial size volumes of fluid.

In preferred embodiments, unit 80 comprises individual cyclones 134 thatare about 0.5 to about 4 inches in diameter; more preferably the nominaldiameter is between about 0.5 and about 2 inches. Unit 80 is preferablyconfigured to operate at a flow rate of at least about 5.5 gallons perminute (0.35 liters per second) per cyclone. More preferably, cyclonicseparator 80 includes cyclones that can process at least about 7.5gallons per minute (0.47 liters per second). The desired flow ratethrough a cyclone can help determine the number of individual cyclonesused in manifold 135. Thus, in certain embodiments of the inventionwhere flow rates are at least about 5.5 gallons per minute per cyclone,the number of individual cyclones can be between about 7 and 60. Thenumber of individual cyclones, however, can be varied according to ananticipated flow rate through the process and the desired removalefficiency of particulate material. For example, a larger flow rate mayrequire more individual cyclones within the manifold.

In a preferred assembly, about twenty openings or slots in manifold 135are available for holding individual cyclones within vessel body 136.Depending on how many cyclones are used in the manifold, unused openingscan be filled with blanks or capped off.

Referring to FIG. 6, separator 80 has an inlet port 138 and an overflowoutlet 140. As seen in the figure, the length of cyclones 134 can extendfrom below vessel inlet 138 to a region adjacent to overflow outlet 140.Cyclones 134 can be secured to an upper plate 142 and a lower plate 144.Preferably, each cyclone 134 contacts upper plate 142 and forms a seal,to minimize leakage of the inlet stream entering port 138 (a reducedparticulate stream) into the overflow stream exiting port 140.

A seal that holds an individual cyclone to its manifold allows thesystem to be sufficiently robust to withstand thermal effects (e.g.contraction and expansion) and prevents unwanted entry and/or mixing ofa reduced particulate overflow stream with the subsequent reducedparticulate stream. However, such seals can be affected by extremeswings in temperature. During operation, a flash zone gas oil stream canbe fed to a cyclonic separator at a temperature between about 600° F.(315.6° C.) to about 800° F. (426.7° C.) during operation. However,during shutdown periods, the cyclonic units may be at much lower ambienttemperatures of about 50° F. (10° C.) to 60° F. (15.6° C.), or evenless, depending on the climate. As is generally known, shutdown andstart-up of operations can challenge equipment, particularly at joints,seals, etc. due to the extreme swings in temperature. Thus, the presentinvention, has overcome these challenges by implementing a seal that canmaintain its seal capability and integrity even through multiple cyclesbetween broad temperature ranges, such as from ambient to 800° F.(426.7° C.), and back.

It has been found that using a configuration of bushings, washers, andgaskets, advantageously creates a sufficient seal between each of thecyclones and both lower plate 144 and upper plate 142. A preferred sealassembly is illustrated in FIG. 7, wherein inside vessel body 136, eachcyclone 134 preferably contacts a lower plate 144 with a gasket 156, andcontacts an upper plate 142 by a bushing 158, washer 160, gasket 162 anda spring washer 164. Preferably, the assembly comprises at least twospring washers. A preferred spring washer is a Bellville or disc washer.Suitable materials for gaskets 156 and 162 comprise material thatremains flexible at high temperatures (e.g. above 600° F. (315.6° C.). Apreferred material is flexible graphite.

Further shown in FIG. 7, cyclones 134 separate a FZGO stream into anoverflow stream that can leave through overflow outlet 140 (not shown,but preferably located between the upper plate 142 and the vessel cap148 as seen in FIG. 6) and an underflow stream (containing the displacedparticulate) that can leave through an apex 146 located at the bottom ofvessel body 136. Apex 146 can be secured to vessel body 136 with anadjustable clamp 166, a centering ring 168, and a gasket 170. In apreferred assembly, apex 146 is removable. Alternatively, apex 146 canbe non-removable and coupled to vessel body 136 using a flange-styleconnection.

The manifold of cyclones can optionally include elongate rods thatconnect the top and bottom plates, 142 and 144, respectively, to providestiffening support to the manifold. The rods minimize potential movementof the vessel plates during thermal changes that occur during operationof the process. Also optionally, an inspection/drain conduit can beprovided to allow drainage of the fluid level. This is particularlyuseful when a unit has to be shutdown for maintenance activities.

FIG. 8 depicts an individual cyclone 134 suitable for configuration intoa cyclonic separator 80. This figure is provided merely to illustratethe fluid flow within a cyclone, where a FZGO stream (illustrated bydashed line) 172 is separated into an underflow stream 174 containingdisplaced particulate material, and a reduced particulate overflowstream 176, the stream having been substantially stripped of particulatematerial. The FZGO stream enters tangentially into cyclone 134 throughan inlet or nozzle 178 and forms a whirlpool or vortex effect. Theparticulate solid material (not shown) generally having a higher density(i.e. heavier) than the FZGO in which it is suspended, is thrown bycentrifugal force away from the center of the vortex. As the particulatesolid material approaches the interior surface wall 182 of the cycloneit moves more slowly and falls by force of gravity to the bottom of thecyclone, where it exits cyclone 134 into underflow stream 174. Theremainder of the FZGO which has been substantially stripped ofparticulate material exits the top of the cyclone as an overflow stream176.

While several particular embodiments of the process and apparatus of theinvention have been illustrated and described, it will be apparent thatvarious modifications can be made without departing from the spirit andscope of the invention. Moreover, references to materials ofconstruction, specific dimensions, and utilities or applications arealso not intended to be limiting in any manner, and other materials,dimensions and utilities or applications could be substituted and remainwithin the spirit and scope of the invention. Accordingly, it isintended that the process and apparatus of the invention not be limited,except as by the appended claims, and that such, other embodiments beincluded within the scope of the following claims.

1-33. (canceled)
 34. In a delayed coking apparatus comprising a cokingdrum that generates overhead vapors, a coker fractionator that receivesthe overhead vapors from the coking drum and separates them into anoverhead vapor stream, intermediate liquid streams, and a flash zone gasoil stream containing a substantial amount of particulate material ofvarying diameter, and a hydroprocessor located downstream from saidfractionator, the improvement comprising: a first separator locateddownstream of said fractionator and configured to receive the flash zonegas oil stream from the fractionator and remove the particulate materialhaving a diameter greater than about 500 micrometers from the flash zonegas oil stream to form a first reduced particulate stream; and a secondseparator comprising a cyclonic separator located downstream of saidfirst separator and configured to remove particulate material having adiameter greater than about 25 micrometers from the first reducedparticulate stream to form a second reduced particulate stream.
 35. Theapparatus of claim 34 wherein said first separator comprises a strainer.36. The apparatus of claim 35 wherein said strainer comprises a basketstrainer.
 37. The apparatus of claim 35 wherein said strainer has a meshsize of about 75 to about 500 micrometers.
 38. The apparatus of claim 34wherein said first separator comprises a cyclonic separator.
 39. Theapparatus of claim 34 wherein said second separator comprises aplurality of cyclones contacting a manifold through a seal.
 40. Theapparatus of claim 39 wherein said second separator comprises at least 7cyclones, each having a diameter between about 0.5 inch and 4 inches.41. The apparatus of claim 39 wherein each cyclone of said plurality ofcyclones has a diameter between about 1 inch and about 2 inches.
 42. Theapparatus of claim 39 wherein each cyclone of said plurality of cycloneshas a diameter of about 1 inch.
 43. The apparatus of claim 39 whereinsaid seal is maintained at temperatures ranging between about ambientand about 800° F. (426.7° C.).
 44. The apparatus of claim 34 furthercomprising a third separator located downstream from said firstseparator and upstream from said second separator.
 45. The apparatus ofclaim 44 wherein said third separator comprises a strainer.
 46. Theapparatus of claims 45 wherein said strainer has a mesh size of about 75to about 500 micrometers
 47. The apparatus of claim 44 wherein saidthird separator comprises a cyclonic separator.